Space travel causes a plethora of medical and neurobehavioural problems, including the loss of as much as 25 percent of muscle mass, a loss of bone mass of between 1 and 2 percent per month, weakening of the immune system, impairments of cognitive performance, and other effects related to the highly stressful environment of a space vehicle.

In M4, :envihab scientists will be able to monitor the physiological changes that could occur during long-term missions. This knowledge, in turn, can be applied to what happens to the body under strenuous conditions encountered on Earth.

Here, researchers will have access to a whole body 3 Tesla MRI/MRS machine with integrated PET. MRI is capable of identifying and monitoring anatomical structures in the human body. Specialised MRI methods measure water and fat content, sodium content or functions like blood flow. Localized MRS (Magnetic resonance spectroscopy) measures the natural content of highly concentrated metabolites, for example, of muscle energy metabolism. A PET scan measures the distribution of tracer substances applied at very low concentrations, which allows for very sensitive and specific measurements of metabolic and physiological processes in the brain and other organs of the body. A particular focus of :envihab scientists will be the imaging of neuroreceptors in the brain involved in sleep-wake regulation and cognitive performance. These investigations are relevant for humans, not only on space missions, but also in operational situations on Earth.

The combination of MRI and PET available in :envihab will make it possible to conduct simultaneous examinations of the human anatomy (with MRI) and physiology (with PET) without unwanted delay and displacement of study participants between tests that are necessary in most other laboratories.